Recording and/or reproducing apparatus adapted to minimized electrical energy consumption

ABSTRACT

A recording and/or reproducing apparatus arranged to permit an interchange of record bearing media and selection between recording and reproducing modes of operation on the medium comprises look-up device for looking up the presence or absence of an existing record in each recording or reproducing position on the record bearing medium loaded on the apparatus, and control unit arranged to control the look-up device to cause it to perform a look-up action in response to opening of a lid for replacement of the record bearing medium and to cut off the power supply upon completion of the look-up action. The control unit thus lowers electric energy consumption and saves electric energy from being wasted by the look-up action.

This is a continuation application under 37 CFR 1.62 of priorapplication Ser. No. 549,271, filed Jul. 6, 1990, which is acontinuation of Ser. No. 462102 filed Jan. 2, 1990, now U.S. Pat. No.5,005,088 which is a continuation of Ser. No. 356,608 filed May 24,1989, now abandoned which is a continuation of Ser. No. 051,477 filedMay 18, 1987, now abandoned.

BACKGROUND OF THE INVENTION

1. Field of the Invention

This invention relates to a recording and/or reproducing apparatushaving a high fail-safe effect.

2. Description of the Related Art

In the recording apparatus of the kind arranged to use a rotary recordbearing medium, such as a magnetic disc or a magnetic drum and to recordby means of a moving head a unit length of information, such as onefield or frame portion of a video signal, in each of recording trackswhich are formed in a concentric or annular shape on the mediumaccording as the information is recorded, the head must be correctlypositioned on the medium at an unrecorded part thereof before recordingthe information in order to avoid double or overlapped recording.

In view of this, some of known apparatuses of the above stated kind havebeen arranged to detect prior to recording the presence or absence ofany record in each recording position on the record bearing medium; toshift the head to a next recording position in the event of detection ofany existing record; to repeatedly perform the head shifting action asnecessary before the head comes to a desired unrecorded part on themedium; and to permit recording after the head is correctly positioned.Such arrangement has been disclosed, for example, in Japanese PatentApplication Laid-Open No. SHO 54-140516 and in U.S. patent applicationSer. No. 030,930, filed Apr. 17, 1979 now abandoned and assigned to theassignee of the present invention.

In the case of the apparatus arranged in the above stated manner, if acontrol sequence is set up, for example, to shift the head to a nextrecording position either upon completion of recording in one recordingposition or before recording in the next position, the present positionon the record bearing medium of the head would serve as a memoryrelative to the next recording position on the medium. Therefore, evenwhen the power supply for the apparatus is switched off or, in the eventof a portable apparatus, when the power source battery thereof is takenout for replacement or charging or when the battery voltage drops to anunserviceable level lower than a threshold value, the possibility of anydouble recording on the same medium can be eliminated and also furtherrecording can be accomplished without leaving any unnecessary unrecordedpart (or a vacant track or tracks) on the basis of the present positionof the head as long as the head has not been moved from the presentposition during an interval time between the present recording andfurther recording.

However, if the record bearing medium is replaced with another recordbearing medium while the power supply is somehow cut off, the presenthead position becomes totally meaningless. Therefore, recording underthis condition might result either in a double record, overlappedrecords or vacant tracks. To avoid such inconvenience, the head must bepositioned at an unrecorded part on the record bearing medium every timethe power supply is switched on. However, this head positioning actionis meaningless in cases where the record bearing medium remainsunreplaced. Besides, it impairs by and large the quick recordingoperability of the apparatus (corresponding to the so-called quickshooting operability of cameras). Further, in the case of a portabletype apparatus, the consumption of the power source battery is quickenedby such arrangement. A problem similar to this likely arises in the caseof an apparatus arranged to necessitate readjustment of recordingconditions such as change-over of the head to be used from one head overto another according to the properties and kind of the record bearingmedium.

To solve this problem, there has been proposed a recording apparatuswhich permits an interchange of record bearing media and is equippedwith some means for mechanically memorizing and storing information onthat a record bearing medium has been taken out or replaced with a newrecord bearing medium. The details of this apparatus are as disclosed inU.S. patent application Ser. No. 826,117, which was filed Feb. 5, 1986,now abandoned assigned to the assignee of the present invention andcorresponding to Japanese Patent Application No. SHO 60-22633. When therecord bearing medium is replaced with another medium, the above statedmemory means mechanically memorizes this fact. In next recording,confirmation is made on the basis of the content of the mechanicalmemory means as to whether the record bearing medium has been replaced.Then, a head resetting action for readjustment of the position of thehead to an unrecorded part of the medium is performed only when the factthat the medium has been replaced is thus confirmed.

In that instance, however, if this mechanical memory means is resetbefore detection of a recordable part of the record bearing medium,occurrence of some power supply trouble (consumption, replacement, or atemporarily cut off state due to an erroneous operation of the battery)or mixing-in of some external noise or the like before detection of therecordable part would make an adequate head positioning actionimpossible.

Further, in resetting the head at an unrecorded part in the above statedmanner to initialize thereby the apparatus in the recording mode,generally a considerably long period of time is required before thestart of an actual image sensing recording operation. During thisperiod, therefore, the power source is generally consumed to a greatdegree. Whereas, there is a strong desire to have the apparatus arrangedto enable the operator to monitor a picked-up image of an objectimmediately after completion of the initializing process.

Further, a recording apparatus of the above stated kind necessitates apower supply, like a still picture camera. However, in taking out therecord bearing medium, if the power supply is not switched on, the headwould remain at an unrecorded part of the record bearing medium. Underthat condition, the medium taking-out action would injure the head.Further, when another record bearing medium is inserted in place of themedium taken out, the head is located at a part corresponding to a firstunrecorded part of the previous medium as viewed from the outercircumferential side thereof. Therefore, after a release switch ispushed, a look-up action must be performed for a first unrecorded partof the newly inserted medium. While the image sensing or recordingapparatus is usable without any other devices for image sensing andrecording, it can be variously arranged, for example, to be capable ofperforming a reproducing function and/or to permit remote control overillumination, etc. by connecting some adapter and some accessory to theapparatus.

In such a case, the adapter and the accessory consume some amount ofelectric energy. If they are provided with no battery for their own usebut are arranged to receive a power supply from the power source of theapparatus, then, this presents a problem with regard to the timing ofthe power supply, because: Constant power supply would shorten the lifeof the battery, would cause corrosion of connectors. It also wouldshorten the serviceable life of electric parts and degrade thereliability of them. Some of these problems would remain unsolved evenif the adapter and the accessory is provided with some power source fortheir own use.

Further, in accordance with the head positioning method mentioned above,if some recording track is erased in an intermediate part of the recordbearing medium, the head is first positioned for the erased track. Inthis instance, the head is shifted to a next recording position aftercompletion of recording in the first position. Then, in shifting thehead to the next position, the presence or absence of an existing recordis also examined and determined. In other words, in the event of avacant track located in an intermediate part, in order to avoid doublerecording, a check must be made for the presence or absence of anyexisting record every time the head is shifted. In that event, anexcessively long period of time is required before next recordingbecomes possible with the head shifted to an unrecorded part. Then, arecording chance (corresponding to the so-called shutter chance of acamera) would be missed or continuous recording, such as a continuousstill video recording for several consecutive fields of frames, wouldbecome impossible because of such a long period of time.

SUMMARY OF THE INVENTION

It is a general object of this invention to provide an image recordingand/or reproducing apparatus which solves all or some of the problems ofthe prior art described in the foregoing.

It is a more specific object of this invention to provide an imagerecording and/or reproducing apparatus which is arranged to suppresselectric energy consumption to a low level.

It is another specific object of this invention to provide a recordingapparatus which is arranged to enable the head thereof to automaticallyhave access to an unrecorded part of a record bearing medium withoutwasting the electric energy for that purpose.

Under this object, a recording and/or reproducing apparatus arranged asa preferred embodiment of this invention to permit replacement of arecord bearing medium and to permit selection of a recording orreproducing mode of operation on the record bearing medium compriseslook-up means for looking up the presence or absence of an existingrecord in each recording or reproducing part of the medium; and controlmeans which is arranged to render the look-up means operative when a lidor cover is opened for replacement of the record bearing medium and tocut off a power supply upon completion of the look-up action of thelook-up means, so that electric energy consumption can be lowered andparticularly energy consumption by the look-up means can be minimized.

It is a further object of this invention to provide a recording and/orreproducing apparatus which is capable of promptly performing a look-upaction by look-up means for detection of the presence or absence of anexisting record on a record bearing medium.

Under that object, a recording and/or reproducing apparatus arranged asa preferred embodiment of this invention is provided with adiscriminating device which comprises: detecting means for detecting thesignal level of each of recording tracks by examining it along thetrack; and discriminating means arranged to determine the presence of anexisting record in the recording track if the result of detection by thedetecting means reaches a predetermined reference level before thesignal level detection is made for the whole of the recording track.

It is a further object of this invention to provide a recordingapparatus which is capable of always accurately bringing a recordinghead to an unrecorded part of a record bearing medium even in the eventof having an external noise mixed in.

It is a further object of this invention to provide a recordingapparatus which is capable of always accurately bringing a recordinghead to an unrecorded part of a record bearing medium even when thepower supply means thereof is in disorder.

Under this object, a recording and/or reproducing apparatus arranged asa preferred embodiment of this invention to permit an interchange ofrecord bearing media comprises: look-up means for looking up thepresence or absence of an existing record in each of recording positionson a record bearing medium loaded on the apparatus; memory meansarranged to store the result of look-up performed by the look-up meansand also to store a check code along with the result of look-up; andcontrol means arranged to discriminate the check code stored by thememory means and to cause the look-up means to perform once again in theevent of an abnormality indicated by the check code due to a disorder inpower supply, an external noise, etc.

It is a further object of this invention to provide a recording and/orreproducing apparatus which has a recording mode and a reproducing modeand is capable of adequately operating even after change-over from therecording mode to the reproducing mode and vice versa.

Under that object, a recording and/or reproducing apparatus is arrangedaccording to this invention to enable the operator to reproduce andconfirm recorded information immediately after recording by justswitching the apparatus from a recording mode over to a reproducingmode.

It is a further object of this invention to provide a recording and/orreproducing apparatus which is capable of accurately and reliablybringing a recording head to an unrecorded part of a record bearingmedium in response to switching from a reproducing mode over to arecording mode.

Under this object, a recording and/or reproducing apparatus which isarranged as a preferred embodiment of this invention to permit aninterchange of record bearing media and to permit selection betweenrecording and reproducing modes of operation on the record bearingmedium comprises: look-up means for looking up the presence or absenceof an existing record in each recording or reproducing position on therecord bearing medium loaded on the apparatus; and a control means forcontrolling the look-up means to cause it to perform the look-up actionthereof in response to change-over from the reproducing mode to therecording mode of the apparatus.

It is a still further object of this invention to provide a recordingapparatus which is arranged to prevent any damage that might occur dueto contact between a record bearing medium and a recording head intaking out the record bearing medium from the apparatus.

Under the above stated object, a recording apparatus which is arrangedas a preferred embodiment of this invention comprises instructing meansarranged to give an instruction for ejecting a cassette; control meansfor keeping a power supply over a predetermined period of time inaccordance with the instruction of the instructing means even when thepower supply is switched off; and means for retracting a recording headby utilizing the power supply turned on in response to the cassetteejecting instruction, so that the recording head and the record bearingmedium can be prevented from being damaged when the medium is taken outafter the power supply is switched off.

These and further objects and features of this invention will becomeapparent from the following detailed description of embodiments thereoftaken in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a block diagram showing an arrangement made in accordance withthis invention.

FIG. 2 is a flow chart showing a basic initializing operation forrecording. FIGS. 3 to 10 are flow charts showing the operation of afirst embodiment of this invention. Of these drawings:

FIG. 3 is a flow chart showing the start of an image sensing action.

FIGS. 4A to 4D are flow charts showing operations in a recording mode.

FIG. 5 is a flow chart showing an operation in a reproducing mode.

FIG. 6 is a flow chart showing an operation performed in switching thepower supply off.

FIG. 7 is an illustration showing the details of the operation of FIG.6.

FIG. 8 is a flow chart showing a motor stop check routine.

FIGS. 9 and 10 are flow charts showing recording initializingoperations.

FIG. 11 is a circuit diagram showing the details of the power supplycircuit of the embodiment of this invention.

FIGS. 12 and 13 are oblique views showing the driving part of therecording and/or reproducing apparatus arranged as an embodiment of thisinvention and a record bearing medium with its carrier.

FIG. 14 is an exploded oblique view showing a cassette loading and discloading device of an embodiment of this invention.

FIGS. 15A, 15B and 15C are sectional views taken along the line A--A ofFIG. 14 respectively showing the device of FIG. 14 as in varied statesthereof.

FIGS. 16A, 16B and 16C are plan views showing in detail the variedstates of a cover lock part of the device of FIG. 14.

FIG. 17 is an oblique view taken from below showing an embodiment ofthis invention and particularly a device thereof for detecting andmemorizing a replacing action performed on cassettes (by dismounting andmounting them).

FIG. 18 is a plan view showing an embodiment of this invention andparticularly a device thereof for shifting a head.

FIG. 19 is a flow chart showing the control flow of a recordingpreparatory operation of a system controller 91.

FIG. 20 is a flow chart showing, as a modification of the above statedembodiment, the control flow of the recording preparatory operation ofthe system controller.

FIG. 21 is a flow chart showing another control flow of the recordingpreparatory operation of the system controller.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Referring to FIG. 1, a recording and/or reproducing apparatus embodyingthis invention and particularly its electrical circuit system isarranged as follows: In the case of this embodiment, this invention isapplied to a still video recording apparatus. The illustration includesa camera part 81 which is arranged in a known manner to form a videosignal; a recording circuit 82 arranged to record the video signal fromthe camera part 81 on a disc 2 via a head 5; a recording control circuit83 arranged to control and cause the recording circuit 82 to recordeither one field or one frame portion of the video signal; and asynchronizing signal generating circuit 84 arranged to generatehorizontal and vertical synchronizing signals HS and VS. The output ofthe circuit 84 is arranged to be applied to the camera part 81, therecording circuit 82, the recording control circuit 83 and a disc motorcontrol circuit 89 which will be described later herein. Further, therecording control circuit 83 is arranged to produce a recording controlend signal RE upon completion of recording by the head 5.

A record presence/absence detecting circuit 85 is arranged to detect viathe head 5 the presence or absence of an existing record of video signalin each recording position on the disc 2. A change-over switch 86 isarranged to switch the connection of the head 5 between the outputterminal of the recording circuit 82 (via the terminal R of the switch)and the input terminal of the detecting circuit 85 (via its terminal C).A switch 107 is arranged either to supply the recording or reproducinghead 5 with a recording signal or to supply a reproduction circuit 108with a reproduced signal from the head 5 via a terminal 110. The outputof the reproduction circuit 108 is obtained from a terminal 109 in theform of a television signal. The reproduction circuit 108 and theterminals 109 and 110 may be arranged to be included in a reproductionadapter PA. In that event, the reproduction adapter PA is arranged to beattachable and detachable to and from the apparatus. Further, thereproduction circuit 108 which is disposed within the adapter PA in thatevent is arranged to receive power supply through a switch 130 under thecontrol of a system controller 91.

A stepping motor driving circuit 87 is arranged to drive a steppingmotor 49 for driving the head. A disc rotating motor 88 is arranged torotate the disc 2 via a spindle 6. A disc motor control circuit 89 isarranged to control the motor 88. In this case, the circuit 89 isarranged to control the motor 88 on the basis of a reference speedsignal produced by a reference signal oscillator disposed within thecircuit 89, a rotating speed signal FG coming from the motor 88, avertical synchronizing signal VS from the synchronizing signalgenerating circuit 84 and a disc rotation phase signal PG coming from adisc rotation phase detector 90 which detects a magnetized pin 3e buriedin the center core 3 of the disc 2. The motor 88 is controlled in such amanner that it rotates at a speed corresponding to the field or framefrequency of the television signal, i.e. 3,600 or 1,800 rpm in the caseof the NTSC system, and rotates at a predetermined phase relative to thetiming of the vertical synchronizing signal VS. This control circuit 89is further arranged to produce a servo lock-in signal SL at a point oftime when the motor 88 comes to rotate at the predetermined speed andphase.

The embodiment is provided with a cassette take out switch 120; and arecording preventing claw detecting switch 121 arranged to detect arecording preventing claw which is not shown but is provided on thecassette containing the disc 2. An on-track detecting circuit 122 isarranged to detect whether or not the head 5 is accurately tracing eachrecording track. For this purpose, the circuit 122 is provided with aphoto-sensor which is arranged to detect a hole corresponding to theposition of each recording track. A power supply switch 123 is arrangedfor the on-track detecting circuit 122. A high level on-track signal 124is arranged to be produced when the head comes to accurately trace thetrack (hereinafter referred to as an on-track state). The on-tracksignal will be described in further detail later with reference to FIG.7.

The system controller 91 is arranged to control the whole circuit systemof FIG. 1 on the basis of the outputs of first and second recordingtrigger switches 95 and 106 which will be described later; those of acassette presence/absence detecting switch 69, a cassettemounting/dismounting detecting switch 70, an outer cover lock completiondetecting switch 74, carrier position detectors 58 and 59, the cassettetake out switch 120, the recording preventing claw detecting switch 121,the on-track detecting circuit 122; the on-track detecting circuit powersupply switch 123; the on-track signal 124; the recording end signal REfrom the recording control circuit 83; the servo lock-in signal SL fromthe motor control circuit 89; and a power-on signal PO obtained when thepower supply is switched on.

The circuit system includes a display device 92 which includes a lightor sound emitting element; a power supply circuit 93 which includes abattery; a backup (or auxiliary) power supply circuit 93' which includesa capacitor; a power supply switch 94; a first recording trigger switch95; a second recording trigger switch 106; and a trigger button 96,which turns on the first recording trigger switch 95 when it is pusheddown to the end of a first step stroke and turns on the second recordingtrigger switch 106 when it is pushed down to the end of a second stepstroke.

The record presence/absence detecting circuit 85 is arranged to detectthe presence or absence of a radio frequency (RF) signal in case thatthe recording signal is, for example, a frequency modulated signal. Inthe event of detection of an existing record, the circuit 85 produces ahigh level signal. The backup power supply circuit 93' is arranged tocharge its capacitor with electric energy upon receipt of a power supplyfrom the power supply circuit 93 with the power supply switch 94 turnedon; to supply the charged electric energy to applicable circuits,including at least the controller 91 and a latch circuit 100, inresponse to turning off of the switch 94; and to have a capacity forscores of minutes to several hours.

A counter 99 is arranged to count driving pulses coming from thestepping motor driving circuit 87. The counter 99 up counts the pulseswhen the stepping motor 49 is driven to rotate forward (to move a headcarrier 46 in the direction of arrow X) in accordance with a controlsignal from the controller and down counts the pulses when the steppingmotor is driven to rotate backward (to move the head carrier 46 in thedirection reverse to the direction of arrow X). The count of the counteris cleared when the carrier position detector 58 which is arranged todetect a 0-th track turns off and is preset at "51" produced from apreset data generating circuit 98 when carrier position detector 59which is arranged to detect a 51st track turns off.

The latch circuit 100 is arranged to latch the content of the counter 99in response to a load instruction produced from the controller 91. Thelatch circuit 100 thus serves as means for electrically storing theresult of look-up for the presence or absence of an existing record. Thecircuit 100 is operated by the power supply from the backup power supplycircuit 93'. A comparison circuit 101 is arranged to compare the contentA of the latch circuit 100 and the content B of the counter 99. When theresult of comparison is A=B, the comparison circuit 101 produces a highlevel output, which is supplied to the controller 91. As will bedescribed later with reference to FIG. 2 and ensuing drawings, thesystem controller 91 is arranged to control also the power supply switch94 by software.

A recording/reproducing mode setting switch 105 is provided on the bodyof the apparatus. For example, the switch is turned on in selecting therecording mode and turned off in selecting the reproducing mode. A block110 represents a remote control device for remote control over therecording and reproducing operations of the apparatus through the systemcontroller 91. Mode setting by this remote control device has priorityover mode setting by the switch 105. The details of the remote controldevice 110 are as described below:

When a remote control operation switch 104 is turned on, an AND circuit102 opens. The output of a recording/reproducing mode selection switch103 is supplied via the AND circuit 102 to the system controller 91. Themode setting by this ON-OFF operating switch is arranged to control themode on the side of the apparatus body taking priority over the modesetting operation of the switch 105.

The cassette presence/absence detecting switch 69 turns on if a cassetteis loaded and set in a recordable or reproducible position. If not, itremains off. The outer cover lock completion detecting switch 74 is inan OFF position when a cover which is not shown but is arranged to benormally closed and to open in replacing the cassette is open and is inan ON position when the cover is closed. The cassette loading/unloadingdetecting switch 70 is in an OFF position when the cassette is notloaded in a recordable or reproducible position. The switch 70 isarranged to turn off upon completion of some initial setting action(such as a recorded track detecting action) even with the cassetteloaded in the recordable or reproducible position. In combination withthe ON and OFF positions of other switches 69 and 74, the switch 70mechanically stores information as to whether the cassette is replacedor not after the above stated initial setting action. More specifically,with the power supply switched on to close the cover, if the switch 70is in its ON position, it indicates that the cassette has been replacedwhile the power supply is off. When the switch 69 is ON and the switch70 is OFF with the cover in a closed state, it indicates that thecassette has not been replaced while the power supply is off. If boththe switches 69 and 70 are in OFF positions with the cover in a closedstate, it indicates that the apparatus is loaded with no cassette.

The detectors 58 and 59 are arranged to detect that the head 5 comes outof a given recording areas on the disc 2 on the outer and innerperipheral sides of the disc 2. These detectors 58 and 59 are providedwith known photo couplers and are arranged to detect a light shieldingplate mounted on the carrier 46. The following description is given onthe assumption that, in the above stated recording area on the disc 2, atotal of 50 recording tracks can be set at a track pitch of, say, 100μm; and these tracks are numbered "1" to "50" in sequence from the outerperipheral side toward the center of the disc 2. In this case, thedetector 58 is arranged to detect the light shielding plate when thehead 5 is shifted further outward to an extent corresponding to onetrack pitch from the first track position (hereinafter this outwardshifted position of the head 5 will be called the 0-th track position).Further, the other detector 59 is arranged to detect the light shieldingplate when the head 5 is shifted one track pitch further inward from the50th track position (hereinafter the inward shifted position will becalled the 51st track position).

The system controller 91 mainly comprises a micro-computer, etc. Thecontroller 91 is arranged to have a power supply also from the backuppower supply circuit 93' in addition to the power supply from the powersupply circuit 93. Its operation which is arranged as a first embodimentof this invention is as described below with reference to the flow chartof FIG. 2:

With the apparatus arranged as described above, when the operator pushesthe button 96 down to the end of its first step stroke after turning onthe power supply switch 94, the first recording trigger switch 95 turnson. Then, a preparatory operation for recording is performed as shown inFIG. 2 in the following manner:

Step S01: The power supply is switched on. Step S02: The systemcontroller 91 makes a check to see if the outer cover lock completiondetecting switch 74 is in its ON state thus indicating that the outercover is closed. If not, the operation flow of the controller 91 waitsuntil the switch 74 turns on. If it is found in an ON state, the flowcomes to a step S03. Step S03: A check is made to see if the cassetteloading/unloading detecting switch 70 is in an ON state. If it is in theON state, it indicates that the cassette 1 has been replaced. In thiscase, therefore, the head 5 is automatically positioned at an unrecordedplace on the disc 2. If the head 5 is shifted while the disc 2 is inrepose, the recording surface of the disc 2 tends to be damaged. Toavoid this, the controller 91 instructs the disc motor control circuit89 to actuate the motor 88. Step S04: In response to the instruction,the motor rotates. Step S05: Then, the stepping motor driving circuit 87is instructed to continuously rotate the stepping motor 49 forward. Themotor 49 comes to make continuous forward rotation. By this, the head 5is continuously shifted toward the center of the disc 2, i.e. in thedirection of arrow X as shown in FIG. 1. Step S06: Meanwhile, thecontroller 91 repeatedly makes a check to see if the carrier positiondetector 59 is turned off by the arrival of the head 5 at the abovestated 51st track position. Step S07: When the detector 59 turns off, aninstruction is given for temporarily bringing the motor 49 to a stop.Following this, if the switch 70 is in an ON state at a step S071, theflow comes to a step S073. If not, the power supply latch is turned offat a step S072.

Step S073: If the switch 70 is in an ON state, the system controller 91checks the counter 99 if the content of the counter indicates the tracknumber "51" in terms of the software. If not, the flow comes back to thestep S02 to repeat the initializing process. A warning may be given ifthere obtains an abnormal state of the apparatus after this process isrepeated several times. Therefore, even if the head position informationobtained from the head shift signal disagrees with an actual headposition due to a noise or the like, the arrangement of this embodimentprecludes the possibility of signal recording in a wrong track.

Step S08: If the content of the counter 99 is "51", the controller 91shifts the connecting position of the change-over switch 86 to theterminal C thereof. Step S09: The output of the record presence/absencedetecting circuit 85 is checked under this condition. Step S10: If theoutput of the circuit 85 is not at a high level, the output of thecounter 99 is temporarily latched by the latch circuit 100. Step S11:After that, an instruction is given for reverse rotation by one step ofthe stepping motor 49. Following this, this action is repeated until theoutput level of the detecting circuit 85 becomes high or the carrierdetector 58 turns off with the head 5 having arrived at the 0-th trackposition at a step S12. The record presence/absence detecting circuit 85is arranged to detect the presence or absence of any existing signalrecord on the disc 2 on the basis of a signal picked up by the head 5.The circuit 85 produces a high level signal in the event of presence ofan existing record and a low level signal in the event of absence.Further, the counter 99 down counts by one every time the stepping motor49 reversely rotates one step.

Step S13: In the operation described above, if the output level of thedetecting circuit 85 becomes high at the step S09 when the head is at anintermediate track, the system controller 91 gives an instruction forcontinuous reverse rotation of the motor 49. Step S14: Meanwhile, acheck is made to see if the carrier position detector 58 has turned off.Step S15: When the detector 58 turns off, an instruction is given tobring the motor 49 to a stop. By this, the head 5 is set in the 0-thtrack position. The counter 99 is cleared. The content of the counterbecomes "0". At that time, the latch circuit 100 retains data of thetrack number of an unrecorded track located next to the last recordedtrack as viewed from the 0-th track.

After the motor 49 is stopped at the step S15, the flow of operation ofthe controller 91 shifts to a next step S16 to give an instruction forreverse rotation of the motor 49 to an extent corresponding to severaltrack pitches (hereinafter referred to as TPs). In this instance, if thedetector 58 has been found to be in an OFF state at the previous stepS12, the flow shifts from the step S12 directly to the step S16 withoutexecuting the steps S13, S14 and S15. Further, in this case, the contentof the latch circuit 100 is at "1". The counter 99 of course has beencleared and the content thereof is at "0" also in this case. In casethat the 50th track has an existing record therein, the flow comes tothe step S13 after making its round of steps S09-S10-S11-S12-S09. Inthat case, therefore, the content of the latch circuit 100 is at "51"and no recording is performed in the 51st track. Further, the content ofthe latch circuit 100 then indicates the position of a track locatednext to and further inward from the last recorded track.

At Step S16: the controller 91 instructs the driving circuit 87 to causethe motor 49 to make stepwise reverse rotation to an extentcorresponding to several TPs to shift thereby the head 5 in thedirection reverse to the direction of arrow X.

Step S17: After the reverse rotation of the stepping motor 49 to theextent of several TPs, the controller 91 this time gives an instructionfor continuous forward rotation of the same motor 49 to shift therebythe head 5 in the direction of arrow X. Step S18: In the meantime, acheck is made for the output A=B of the comparison circuit 101. Then,the counter 99 up counts to have its content incremented one by one from"0" according as the stepping motor 49 rotates forward. In other words,the content of the counter 99 always indicates the position of the head5 on the disc 2 and thus gives a track signal. When the number assignedto a track to which the head 5 is presently opposed comes to coincidewith the content of the latch circuit 100, the comparison circuit 101produces its output A=B at a high level. Step S19: When the level of theA=B output of the comparison circuit 101 becomes high at the step S18,the controller 91 gives an instruction for stopping the motor 49. Thehead 5 is thus set in a track position indicated by the data retained atthe latch circuit 100. In other words, the head is positioned at a track(unrecorded) which is located next to the last recorded track as viewedfrom the 0-th track.

Step S20: The controller 91 then gives an instruction to bring the discmotor 88 to a stop. Step S21: After that a check is made to see if thecarrier position detector 59 is in an OFF state. Step S22: If not, thedisplay device 92 is caused to make a display indicating a recordablestate, or completion of preparation for recording. Step 23: In case thatthe detector 59 is in the OFF state, the display device 92 is caused tomake a display indicating completion of recording in the 50th track onthe disc 2 (or the end of the disc). Step S24: Further recording isinhibited.

Meanwhile, if the cassette loading/unloading detecting switch 70 isfound not in an ON state at the step S03, it indicates either that thecassette 1 (see FIG. 13) is not replaced (no loading and unloading) orthat the apparatus is loaded with no cassette. Step S25: In that event,therefore, the controller 91 checks the cassette presence/absencedetecting switch 69 to see if it is in an ON state thus indicating thepresence of the cassette 1. If so, the flow of operation comes back tothe step S21. If not, it indicates the absence of the cassette. StepS26: In that event, the controller 91 causes the display device 92 tomake a display indicating the absence of the cassette. Step S24: Then,recording is inhibited. After that, at a step S221, a power-off routineis executed for turning the power supply off. An interrupt routine S000is arranged to be executed as follows when the switch 74 turns off froman ON state: Step S001: The power supply is first latched. The flow thenproceeds to the step S04. Following this, steps S05 to S071 areexecuted. The flow comes to a step S072. Therefore, the head 5 is alwaysshifted to and stopped at the 51st track when the cover is opened. Thispermits quick execution of the ensuing initializing process. Thisembodiment thus accomplishes a preparation for recording in the manneras described above.

FIGS. 3 to 8 are flow charts showing the operation of a secondembodiment of this invention. Referring first to FIG. 3, the secondembodiment operates as follows: Step S25': The power supply switch 94turns on. Step S26': The battery is checked with a first thresholdvalue. Step S27: In the event of a low level of the battery, a warningis given urging replacement of the battery. Step S28: Again batterycheck is made. This time, the check is made with a threshold value whichis lower than the first threshold value to see if the battery retains aminimum electric energy level required for image sensing and recording.Step S29: If not, the power supply switch 94 is turned off. The flow ofoperation waits until the battery is replaced with a new battery. StepS30: If the energy level of the battery is found sufficient at the stepS26 or S28, a check is made first of all for any mode interruption fromoutside by remote control means. Step S31: If so, the interrupting modeis discriminated. If the mode in question is found to be a recordingmode, the flow shifts to a routine (B). If it is found to be areproducing mode, the flow shifts to a routine (C).

In the event of no mode interruption, the flow comes to a step S32. StepS32: The mode switch 105 of the apparatus body is checked. Then, like inthe case of the step S31, the flow shifts to the routine (B) or (C)according as the switch 105 indicates the recording mode or thereproducing mode.

Referring now to FIGS. 4A to 4D, the operation in the recording mode isas follows: At a step S33, a check is made for disc motor rotationstarting conditions. In other words, the motor is inhibited from beingstarted if any one of the following conditions is found:

Condition 1: When the cassette presence/absence detecting switch 69 doesnot show any cassette.

Condition 2: When the outer color lock completion detecting switch 74 isfound in a state showing that the outer cover has not been completelylocked.

Condition 3: With the cassette take out switch 120 which is to beoperated in taking out the cassette examined, if the switch 120 is foundin a state showing that the cassette is in process of being taken out.

Condition 4: With the recording preventing claw detecting switch 121examined in the recording mode, if the switch 121 is found in a stateshowing that the cassette is in a recording prevented state.

Condition 5: In the recording mode, when the count number of recordedframes as stored at the electrical storing means has already reached apredetermined number.

Condition 6: With the carrier position detector 59 examined in therecording mode, if the detector 59 is found in a state showing that thehead is positioned in the innermost part of the disc thus indicating acompletely recorded state of the disc loaded on the apparatus.

If none of these conditions apply, the flow of operation proceeds to astep S34. Step S34: The disc motor is driven to rotate to bring the discinto a recordable state. Step S35: A check is made to see if theapparatus has been in the reproducing mode. If so, the flow comes to astep S37. If it is found to have been in the recording mode, the flowproceeds to a step S36. In case that the apparatus has been in thereproducing mode, the track number stored either at the latch circuit100 or at a memory M (not shown but is disposed within the controller91) by an initializing process which is similar to the preparatoryaction for recording shown in FIG. 2 as will be described later mighthave deviated from the actual head position by frequent shifts oftracks. The checking action at the step S35 solves this problem. If theapparatus is found at the step S35 to have been continuously in therecording mode, checksum judgment is made on the latch circuit 100 orthe memory M at the step S36 as will be further described later. If thecontent of the memory is judged to be correct, the flow shifts to arecording operation to be performed at steps beginning with a step S47.Step S37: An initializing flag IF is set at the memory which is backedup by the backup power supply in preparation against cutting off ofpower supply during an initializing process. Step S38: The initializingprocess is performed in a manner as will be described later. Step S39:Upon completion of the initialization, the flag IF is reset.

In the checksum process at the step S36, while the track number isstored at the latch circuit 100 or the memory M backed up by the backuppower supply, checksum data such as data of 4 bits (0101) or (1010) orthe like is written in along with the track number data when the powersupply is cut off. In the event of an abnormity of the action of thememory M or the latch circuit 100, these checksum bits change to 1111 or0000 in most cases. At the step S36, therefore, an exclusive OR isobtained from such a code as (0101) or (1010) and the checksum bits. Ifthese bits all become "0" as a result of this, the data in question isjudged to be normal. If not, it is judged to be abnormal. The datawritten in the same memory can be thus determined to be correct orwrong. In the event of an abnormity in the track position signal due toa noise mixed in the electric circuit, for example, no signal will berecorded by mistake in a track having an existing record therein.

Step S47: With the checksum found to be OK (all right) at the step S36,a power supply to the on-track detecting circuit 122 is switched on.This circuit 122 is arranged to find whether the head 5 is placed in apredetermined position on the disc 2. Step S48: The head 5 is broughtinto contact with the disc 2. Step 49: The output of the on-trackdetecting circuit 122 is checked to see if the head 5 is in an on-trackstate. If not, the flow comes to the step S37 to perform the recordinginitializing process over again. In other words, in the case of thisembodiment, a check is made to see if the head 5 is correctly positionedat a recording track on the recording medium (disc) or located at aguard band in between two recording tracks when the head is brought intocontact with the medium at the step 48. If the head is found notcorrectly positioned at the recording track, the initialization forrecording is carried out over again. If the head is found to be in the"on-track" position, the flow shifts to a step S40. Step S40: Again acheck is made for the state of the release switch SW1. If the switch SW1is found to be in an ON state, the flow proceeds to a step S41. If not,the flow comes back to the routine (A) which begins with the step S25'.Then, the steps of operation mentioned above are repeated.

Step S41: If the apparatus is found not in the recording mode, the flowcomes back to the routine (A). If it is found to be in the recordingmode, the flow comes to a step S42. Step S42: The second release switchSW2 is checked to see if it is in an ON state. If not, the steps S40,S41 and S42 are repeated until the switch SW2 turns on. The flow thenproceeds to a step S43. Step S43: An image sensing and recordingoperation is performed. After this, the flow comes back to the step S49.

FIGS. 4B, 4C and 4D show the details of the step S43. Step S430: Like inthe step S26', the battery is checked to see if it is at a low energylevel. If so, the flow first comes to a step S433. Step S433: The headis brought into contact with the disc. Step S434: Then, a mirror isretracted away from an optical path. Meanwhile, if the energy level ofthe battery is found to be high, the flow proceeds to a step S431. StepS431: The mirror is retracted from the optical path. After that, theflow comes to a step S432. Step S432: The disc is brought into contactwith the disc. This step is provided for the purpose of giving priorityto the positional relation between the head and the disc in case ofsudden deterioration of the battery.

Step S435: The aperture of the camera part is stopped down to apredetermined value. Step S436: White balance is adjusted. Steps S437and S438: A check is made to see if mirror uplifting (retracting) andaperture stopping-down actions have been completed. If so, the flowcomes to a step S439. Step S439: The shutter of the camera part isopened. Step S441: The shutter is closed to bring an exposure to an end.

Step S443: Recording is performed. Step S444: Again the battery ischecked to see if the energy level of the battery is low. If so, theflow comes to a step S454 of FIG. 4D. If not, the flow proceeds to astep S445. Step S445: The shutter of the camera part is charged. In themeantime, an ID signal is encoded. Then, an error detection code, etc.are added to the ID signal. The ID signal is provided for the purpose ofrecording information about the recording track number, etc. in a stateof being superimposed upon a video signal. This step somewhat quickensthe speed of the whole program. The flow then proceeds to a step S446.Step S446: The head is shifted forward by one track pitch. The flowproceeds to a step S447. Step S447: The track number is incremented byone. Meanwhile, if the level of the battery is low, it might come tosuddenly drop before the end of a process. Therefore, in that event, theflow comes to the step S454. Step S454: The position of the head isfirst shifted. Step S455: Then, the track number is renewed. Step S456:The shutter is charged and the ID signal is formed. The flow then comesto a step S448. Step S448: A check is made for the ON state of theswitch SW2. If is it in the ON state, the image sensing recordingoperation is assumed to continue. The flow then comes to a step S449.Step S449: A check is made to see if the operation is in the mode ofhigh speed continuous shooting. Further, a check is made to see if aflash device which is not shown is in a charge-up state. If so, the highspeed continuous shooting is impossible. In that event, therefore, theflow comes to a step 451. If the flash device is found not in thecharge-up state or if no flash device is used, the flow comes back tothe step S439 to repeat the photo taking sequence of processes.

Step S451: The mirror is moved back to the inside of the optical path.The aperture is opened. Step S452: A check is made to see if theapparatus is in a low speed continuous shooting mode. If so, the flowcomes back to the step S430. If not, the flow comes to a step S453. StepS453: A power-off routine is executed. The program of operation thencomes to an end.

Referring to FIG. 5, the operation in the reproducing mode is asfollows: Step S47': Like in the recording mode, the disc motor rotationstarting conditions are examined. Step S48': The disc motor is driven torotate. Step S49': A check is made to see if the apparatus have been inthe recording mode. If so, the flow comes to a step S50 and ensuingsteps. If not, the flow shifts to a step S53. Step S50: A check is madeto see if the present track number is "0". If so, reproduction isconsidered impossible and the flow comes to steps S57 to S59 to executean initializing process in a manner similar to the steps S37 to S39 ofFIG. 4A. In case that the present track number is found not "0" at thestep S50, the flow proceeds to a step S51 to make a check for thechecksum in a manner similar to the step S36 of FIG. 4A. Step S52: Ifthe result of this is OK, the head is shifted to a track immediatelypreceding the present track. In other words, the head is shifted to atrack recorded immediately before the present head position. Thisarrangement permits immediate recording in the recording mode andimmediate confirmation of information last recorded in the reproducingmode. Further, in the case of the reproducing mode, this step saves theoperator from having a disagreeable feeling which would be caused by anunrecorded track otherwise appearing in the beginning of reproduction.

Step S53: A check is made to see if a given length of time has lapsedfrom the time of the step S25' of FIG. 3. If so, the reproducing mode isassumed not to be continued. The flow then comes to a step S54. StepS54: The power supply is switched off and the flow comes back to theroutine (A). If the length of time is found not to have lapsed at thestep S53, the reproducing mode is assumed to be continued and the flowcomes to a step S55. Step S55: A check is made to see if the apparatusis in the reproducing mode. If not, the flow comes to the routine (A).If so, the flow comes to a step S56. Step S56: Reproduction isperformed. During the process of reproduction, the discriminatingactions of the steps S53 and S55 are incessantly performed.

In this instance, a timer is used and the power supply is arranged to becut off after the lapse of a given period of time. In case that thereproduction circuit is arranged to be connected to the outside of theapparatus as an adapter PA for reproduction, the step S53 may bereplaced with another step S53' at which the power supply to thereproduction adapter PA begins. In that instance, the power supply tothe reproduction adapter is kept off until execution of the step S53'.This arrangement not only saves the energy of the power source frombeing wasted but also prevents a connector used for the terminal 110 ofFIG. 1 from corroding.

Referring to FIG. 6, the power off routine shown in FIGS. 3 to 5 arearranged as described below:

Step S60: The drive output of the disc motor 88 is turned off. Step S61:The head 5 is retracted away from the disc 2. Step S610: A checksum isadded to the track number stored at the latch circuit 100. Step S62: Themain power supply is switched off to bring the operation to an end. Themethod for retracting the head at the step S61 is as described below:

Referring to FIG. 7, this embodiment is arranged to drive the head by 12steps for each track pitch TP. The head is arranged to be shiftedrelative to the disc through a cam which is arranged to cooperate withthe stepping motor in such a manner that: The head stays away from thesurface of the disc during the periods approximately from first tofourth steps and from ninth to twelfth steps. The head comes intocontact with the surface of the disc between the fifth and eighth steps.

The present step position of the stepping motor is recorded at a memorywithin the control circuit and is duodecimally renewed every time thestep motor 49 is driven. In retracting the head 5, therefore, the stepmotor 49 is driven to shift the head 5 to a position at a track locatedclose to the first step.

Referring to FIGS. 9 and 10, the details of the initializing routineshown in FIGS. 4A and 5 are as shown in steps S68 to S77. Step S68: Likein the step S34 of FIG. 4A, control over the disc motor 88 begins. StepS69: A power supply to the on-track detecting circuit 122 is switchedon. Step S70: The stepping motor 49 is caused to continuously rotateforward for driving the head. Step S71: The head 5 is driven inwarduntil the carrier position detector 59 turns off with the head shiftedto a position between the 51st and 52nd tracks. Step S72: The steppingmotor 49 is caused to further rotate forward an N number of steps (N: aninteger between 0 and 12) to ensure that the head is shifted to theinnermost position on the disc.

Step S73: After the step S72, in order to drive the stepping motor 49more stably than usual driving, the flow of operation has a wait time,which is about 2 to 3 times as much as the energizing time required perstep of the stepping motor. Step S74: After the lapse of the wait time,the stepping motor 49 is caused to reversely rotate to shift thereby thehead toward the outer periphery of the disc. The steps S73 and S74 arerepeated until the carrier position detector 59 turns on with itsposition changed over between the 51st and 52nd tracks. Step S75: Acheck is made to see if the detector 59 is in an ON state. If so, theflow comes to a step S76. Step S76: The level of the on-track signal 124is checked to see if the head is positioned approximately in the middlepart of the track, i.e. whether the head is in an on-track state. Ifnot, the flow has a wait time at steps S78 and S79 in the same manner asin the steps S73 and S74 to ensure that the head is accurately shiftedtoward the periphery of the disc step by step. The flow then comes backto the step S76. When the head is found to be in the on-track state atthe step S76, the flow comes to a step S77. Step S77: The track counteris initialized with the head position which is obtained at that timeconsidered to be the innermost on-track position.

Step S80: A check is made for discrimination between the recording modeand the reproduction mode. The flow then branches out to thereproduction initialization to be performed at steps S81 to S83 or tothe recording initialization to be performed at a step S84 and ensuingsteps according to the result of the discrimination. The initializationfor reproduction is as follows: Step S81: In the case of thereproduction mode, the head is first shifted to an arbitrarilydesignated track position. The designation of a track to be reproducedis made from outside by means of a ten-key or up-down key arrangement,the details of which is omitted herein. In the event of no designationof any particular track for reproduction, the head is shifted to thefirst track which is located in the outermost part of the disc.

Step S82: Tracking control (automatic tracking finding) is performed byusing the output of the record presence/absence detecting circuit 85 insuch a way as to have a recorded signal reproduced from the designatedtrack at the optimum level. Step S83: The on-track detecting circuit 122is turned off to bring the initializing action to an end. At that time,the power supply of the whole apparatus is kept unchanged.

Next, initialization for recording is as follows: Step S84: In the eventof the recording mode at the step S80, the switch 121 is checked for arecording preventing state of the cassette. If the cassette is thusfound in a state of having no recording preventing claw, the flow shiftsto a step S93 of FIG. 10. If not, the flow proceeds to a step S85. StepS85: A check is made to see if the present position of the head is atthe innermost track among all the recordable tracks (the 50th track inthe case of this embodiment). Assuming that the total number of tracksis 51, the 51st track is often used for recording a signal for someother purpose different from other tracks, such as disc controlinformation, etc. In that event, the innermost recordable track is the50th track. Step S86: The head is shifted outward by one track pitchdistance to the innermost recordable track (the 50th track in thisinstance). The flow then proceeds to a step S87.

Steps S87 to S92 are provided for finding out a recording track positionand are arranged as follows:

Step S87: A wait time is provided until the head position is stabilized.After the lapse of the wait time, the flow comes to a step S88. StepS88: The level of signal reproduction from the track is detected and thetrack is determined to be recorded or unrecorded by the recordpresence/absence detecting circuit 85. If the track is thus found to beunrecorded, the flow comes to a step S89. Step S89: A check is made tosee if the present position of the head is at the first track. If not,the stepping motor 49 is reversely rotated by one track pitch in thedirection of the periphery of the disc. The flow then comes back to thestep S87.

If the head position is found to be at the first track at the step S89,the disc presently loaded on the apparatus is determined to beunrecorded. Then, data is stored indicating that the track in whichrecording is to be made from now is the first track. In other words, forexample, "1" is stored at the memory M labeled "RECT" within thecontroller.

In case that the present track is found to be a recorded track at thestep S88, the track number of a track located next to the present trackon the inner side thereof is stored as the track to be recorded fromnow. In other words, the count of the track counter obtained at thattime is incremented by one and is stored at the memory "RECT". Step S93:With the position of the track to be next recorded thus determined, thecassette loading/unloading detecting switch 70 is turned off for storinginformation about the end of a vacant track detecting action. For thatpurpose, the stepping motor 49 is driven toward the periphery of thedisc. Step S94: Then, when the content of the track counter becomes lessthan "1" or when the carrier position detector 58 turns off, the flowcomes to a step S95. Step S95: The rotation of the stepping motor 49 isbrought to a stop. Step S96: Then, a check is made to see if thecassette loading/unloading detection switch 70 is in an OFF state. Ifso, the flow comes to a step S961 to make a check to see if therecording preventing claw of the cassette is broken. If so, the flowcomes to a step S962 to cause the motor 49 to make forward rotation.When the position detector (or switch) 59 turns off at a step S963, theflow comes to a step S99 at which the power-off routine is executed.Meanwhile, if the cassette is not in the recording preventing state, theflow comes to a step S97. Step S97: The head is first shifted to aposition corresponding to data stored at the memory "RECT" in the stepsS91 and S92. In this instance, the system controller 91 causes thestepping motor 49 to be driven at a speed higher than the stepping motordriving speed employed for the steps S70, S72, S74, S78, S81, S86, S90and S93. More specifically, driving pulses of a higher frequency areapplied to the motor in this instance. Further, the stepping motor isdriven at the higher speed also at the above stated step S962.

Since the embodiment is arranged as described above, the stepping motor49 must be driven at a lower speed for detecting the presence or absenceof a recorded signal existing in each of the tracks in search of avacant track. Whereas, in the case of the step S97, the head shiftingaction is quickly completed without keeping the operator waiting forlong.

Step S98: The on-track signal 124 is checked for confirmation of thatthe head is in the optimum track position on the disc. If the on-trackstate of the head is thus confirmed, the flow proceeds to a step S99.Step S99: The power-off routine for turning off the power supply for thewhole apparatus is executed. The initializing action for recording thencomes to an end. The arrangement to turn off the power supply uponcompletion of initialization for recording saves electric energy. In thereproducing mode, on the other hand, the power supply is not cut offafter completion of initialization as the record is usually reproducedimmediately after completion of initialization for reproduction.

In case that the switch 70 is found not in the OFF state at the step S96or the head is found not in the on-track state at the step S98, the flowcomes to a step S100 at which an error processing action is carried out.The error processing action may be arranged to make a warning display orto carry out the initializing action again. Further, although it is notshown in the drawings, an appropriate error processing action may beperformed in the event of occurrence of any abnormity during theexecution of the steps shown in FIGS. 2 to 10.

In this embodiment, the switch 70 is arranged to turn off when the head5 is shifted to a part located on the outer side of the No. 0 track onthe disc. Further, in the case of an electronic camera, for example, thedisc motor might be mechanically damaged in general when the disc andthe disc motor is released from their checking state while the motor isrotating. To avoid this, therefore, this embodiment is arranged to makea check and then the motor is brought to a stop in the case of partingthe disc from the motor in a manner as shown in FIG. 8. This operationis as follows: Step S63: A check is made to see if the operator isoperating the cassette take-out switch 120. If so, the disc and themotor are expected to be soon released from their chucking engagement.Step S66: Therefore, the brake is applied to the motor to bring themotor to a stop. Following this, the power off routine of FIG. 6 isexecuted as stated in the foregoing. Further, if the cassette take-outswitch 120 is found not under operation at the step S63, the flowproceeds to a step S64. Step S64: A check is made for completion of anouter cover locking process. This step is provided for the purpose ofpreventing an erroneous check due to inappropriate checking timing. Incase that the outer cover locking has not been completed at the stepS64, the flow comes to the step S66. If it is found to have beencompleted, the flow comes to a step S65. Step S65: This step is providedfor preventing any error of the checks made at the preceding steps S63and S64. If the cassette is found to be absent, the flow comes to thestep S66. If the cassette is present, the flow comes to execute anensuing process.

These steps S63 to S65 may be executed either while the motor isrotating or may be constantly executed at intervals of a given period oftime. It is also possible to execute these steps in an interruptingmanner by means of a switch 120. Further, the above stated process maybe changed in cases where the system arrangement permits highly reliableprior detection of parting of the disc and the motor from each othersolely by the check made at the step S63. The process may be alsochanged to detect the position of the cassette take-out switch and tohave the cassette ejected after the motor is stopped instead ofelectrically ejecting the cassette. Further, the electrical brakeapplication to the motor may be changed to mechanical brake application.The braking effect may be enhanced by bringing the head into contactwith the motor. In this case, the head is retracted after the motorcomes to a stop.

In the system described, the head is arranged to be shiftable relativeto the disc. However, the system may be arranged to shift a pad which isarranged to bring the head into contact with the disc. In that case, thesequence of processes described above may be changed to have the pad,instead of the head, retracted from and brought into contact with thedisc.

While this invention is applied to a video signal recording apparatus inthe case of the embodiment described in the foregoing, the invention isapplicable also to an apparatus for recording an audio signal orinformation such as data. Furthermore, the recording method to whichthis information is applicable is not limited to magnetic recording. Therecord bearing medium usable according to this invention is not limitedto the disc shaped medium but may be a medium of a drum-like shape or atape-like shape, such as the one used by an 8-track audio recorder.

FIG. 11 shows by way of example the details of the power supply circuit93 of FIG. 1. The circuit diagram of FIG. 11 includes a battery or an ACpower supply 400; each applicable circuit 401; switching transistors 402and 403; a capacitor 404; resistors 405 to 411; and diodes 412 to 420.The resistor 406, the diode 413 and the capacitor 404 jointly form acharging circuit for pulling the base current of the transistor 403 intothe capacitor 404. The diode 412 and the resistor 408 form a dischargecircuit for the capacitor 404. Further, the resistor 407 is alsoincluded in the discharge circuit for the capacitor 404. When thecassette take-out switch 120 or the cassette loading/unloading detectingswitch 70 is turned on, a current from the power supply 400 flowsthrough the resistor 406, the diode 413, the capacitor 404; the diode415 (417) and the switch 120 (70). Then, the switching transistor 403turns on and remains in the ON state until the capacitor 404 is chargedwith the current. With the transistor remaining in the ON state duringthe period before the capacitor 404 is charged, the system controller 91is supplied with electric energy. This actuates and enables thecontroller 91 to detect the switching states of the switches 120, 70 and95. When the ON state of the cassette take-out detecting switch 120 isdetected, the system controller instructs the stepping motor drivingcircuit 87 to have the head 5 retracted to a retracting position thereofshown in FIG. 7. In case that the head is completely retracted beforecompletion of the charging process on the capacitor 404, the powersupply to the applicable circuits is cut off with the transistor 403automatically turned off following completion of the capacitor chargingprocess. In case where the head is not retracted within the period oftime required for charging the capacitor 404, the system controller 91keeps the transistor 403 in its ON state by turning the transistor 402on until completion of the head retracting process. In that case, thepower supply is thus continuously applied particularly to the steppingmotor driving circuit 87.

Further, when a lock lever 221 which will be described later begins tobe operated, at the beginning of the lever operating process, thecassette take-out switch 120 immediately turns on. This gives some timelag before an outer cover 235 is opened by the lever operation and thusallows the head 5 to be shifted to the head retracting position beforethe outer cover 235 is actually opened. Therefore, the head 5 and themagnetic disc 2 can be prevented from being damaged.

In this specific embodiment, the cassette loading/unloading detectingswitch 70 is connected in parallel with the switch 70. Therefore, whenthe switch 70 turns on with the cassette replaced with another cassette,the switching transistor 403 becomes conductive in the same manner aswhen the switch 120 is turned on. This enables the power supply to beapplied to the system controller 91 as well as to each applicablecircuit. Then, the above stated initializing action is carried out. Thesystem controller 91 keeps the transistor 402 in its ON state tomaintain the power supply to each applicable circuit until completion ofinitialization.

Upon completion of the initializing action, the system controller 91causes the transistor 402 to turn off, so that the electric energy canbe saved from being wasted. Further, with the cassette loading/unloadingdetecting switch 70 connected in parallel with the switch 120, the othertransistor 403 is arranged to be turned on via the capacitor 404.Therefore, in case that the switch 70 is unable to return from an ONstate to an OFF state with no initializing action performed due to somereason, wasteful electric energy consumption can be prevented fromoccurring due to a persistent conductive state of the transistor 403.This is a great advantage in terms of electric energy saving.

Meanwhile, the switch 95 which is arranged to be turned on by the firststep stroke of the release button 96 is connected directly to the baseof the transistor 403 without having any capacitor interposed in betweenthem. Therefore, the transistor 403 continues to be in its ON state aslong as the switch 95 is in an ON state. This allows the power supply tobe applied to each applicable circuit without fail under that condition.

The advantages of this embodiment:

a. In the reproducing mode, the power supply remains on after completionof initialization. However, in the recording mode, in which the time fora next image sensing recording operation is uncertain, the power supplyis cut off upon completion of initialization. This ensures a greatelectric energy saving effect in the recording mode on one hand and agood operability in the reproducing mode on the other as the reproducedpicture can be monitored immediately after the cassette is loaded.

b. In the reproducing mode, frequent shifts of the head position tend toresult in some deviation of the electrical head control signal from anactual head position. Even in that event, the invented arrangementeliminates the possibility of signal recording in a wrong track.

c. In case that the electrical control signal is disturbed by someexternal noise due to a head shifting action, the invented arrangementeliminates the possibility of recording in a wrong track.

d. In detecting replacement of the cassette, the power supply is kept onfor a given period of time after the cassette is replaced with a newcassette in accordance with the output state of the detecting means.This enables the newly loaded cassette to be initialized beforerecording or reproduction. After that, recording or reproduction can beperformed any time as desired.

e. In the event of use of an external discrete device such as thereproduction adapter, for example, the power supply to the externaldevice is inhibited until completion of the initial positioning actionon the head relative to the record bearing medium as mentioned at thestep S53 of FIG. 5 or the step S53': This arrangement prevents theenergy of the power source from being wasted. Further, the arrangementeliminates the possibility of abnormal consumption of the electricenergy for the initial head positioning action.

In the embodiment and its modifications described in the foregoing, therecording tracks on the disc are numbered in sequence from theperipheral side of the disc toward the center of the disc. However, thedirection of this track numbering sequence may be reversed. In thatevent, the flow of operation shown in the drawings should be somewhatchanged accordingly.

In the case of the embodiment described, this invention is applied to acamera-combined type still video recording apparatus. However, thecamera part 81 of course may be replaced with some discrete cameradevice. Further, the power source of the recording apparatus is notlimited to the battery. The apparatus may be arranged to permit use of acommercial power source.

The record bearing medium which is usable by the embodiment and themedium loading device of the embodiment are arranged as described below:

The record bearing medium usable by an embodiment of this invention isarranged as shown in FIGS. 12 and 13. FIG. 12 is an oblique view of arotatory driving spindle 6. FIG. 13 is an oblique view of a cassette 1carrying a magnetic disc 2 which is employed as the record bearingmedium to be rotated by the above stated spindle 6. The magnetic disc 2is a rotatable flexible body and is disposed within the cassette. Acenter core 3 which is made of a synthetic resin is located in themiddle part of the magnetic disc 2. To the lower side of the center core3 is secured a magnetic plate 3d (see FIGS. 15B and 15C). A magnetizedpin 3e which is arranged to indicate the rotation phase of the disc isprovided on the magnetic plate 3d and is arranged to pierce through thecenter core 3. Apertures 1a and 1b are provided on the upper and lowersides of the cassette 1. These apertures are arranged to permitingression of stabilizing plates 37 and 15 (see FIG. 14) which areprovided for stabilization of the rotation of the magnetic disc 2. Thelower side aperture 1b also permits the recording magnetic head 5 tohave access to the recording face of the magnetic disc 2 therethrough.

The center core 3 is arranged to be mounted on the magnetic discrotating driving spindle 6 which is disposed on the loading side of theapparatus. The center core 3 is provided with an engaging hole 3c, whichis formed by two slanting face parts 3b and a spring part 3a. The springpart 3a is arranged to push the slanting face parts 3b against thespindle 6. A permanent magnet 7 is arranged on a flange part 6a of thespindle 6 to confront the magnetic plate 3d which is disposed on thelower side of the center core 3. The so-called magnetic chucking takesplace with the magnetic plate 3d pulled by the permanent magnet 7 on thespindle 6 when the center core 3 is mounted on the spindle 6. On thatoccasion, the height of the magnetic disc 2 relative to the head 5 isdefined as the lower side of the center core 3 comes to abut on theflange face 6b of the flange part 6a of the spindle 6. The cassette 1 isprovided further with upper and lower apertures 1c and 1d which areformed in a position corresponding to the center core 3.

The embodiment of this invention using a magnetic disc arranged in thecassette in the manner as described above is provided with a mechanicaldevice which is arranged for the use of the disc as described below:

Referring to FIG. 14, the illustration includes a chassis 11 of therecording apparatus. The spindle 6 and the head 5 are rotatable andshiftable on the chassis 11. The chassis 11 is provided with a hingeshaft 12 and a side plate 16. A shaft 17 is erected on the side plate16. A clamping lever 18 is rotatably mounted on the shaft 17 and isurged to turn round clockwise by a spring 19. A pair of pins 20 isarranged on the side plate 16 to guide two slidable lock levers 21 and23. The levers 21 and 23 are urged to move leftward by springs 22 and24, which are attached to pins 41 and 42. The pins 41 and 42 are alsoerected on the side plate 16.

A cassette holder 31 is arranged to receive the cassette. The holder 31is turnable on the hinge shaft 12 relative to the above stated chassis11 of the apparatus body. The holder 31 is provided with an opening part31f which opens on one end of the holder 31 for receiving thecassette 1. The holder 31 is provided further with apertures 31a and 31bfor permitting stabilizer plates 37 and 15 to enter the holder 31; andalso with apertures 31c and 31d which are arranged to permit the spindle6 and a protrudent part 38a of a center core pushing leaf spring 38 toenter the holder.

Another aperture 31g of the holder 31 is arranged on the lower side ofthe holder 31 to permit the entrance of a cassette sensing piece 66a ofa cassette loading/unloading detecting lever 66 (see FIG. 17) into theholder. An outer cover 35 is attached to the body chassis 11 in such away as to be turnable on the hinge shaft 12 through the hinge part 35athereof. Lock pins 36a and 36b are erected on the fore end side face 35cof the outer cover 35. The outer cover 35 is also provided with a hookmember 40 which is arranged to engage the holder 31. An upperstabilizing plate 37 which is attached to the ceiling part of the outercover 35 is arranged in combination with a lower stabilizing plate 15which is disposed on the side of the body chassis 11. These stabilizingplates 37 and 15 are arranged to have the magnetic disc 2 interposed inbetween them and to prevent the disc 2 from vibrating and deforming whenit rotates. In that instance, a suitable layer of air is formed betweenthe disc 2 and each of the stabilizing plates 37 and 15. The head 5 isarranged to protrude through an aperture 15a provided in the middle partof the lower stabilizing plate 15. A leaf spring 38 in the form of aT-shaped plate has its tail end 38b secured to the ceiling part of theouter cover 35 by means of a screw or the like. A portion 38a of thefore end of the leaf spring 38 is arranged to protrude downward as shownin FIG. 14. Position defining members 39 which are attached to theceiling part of the outer cover 35 engage the edge parts 38c on bothsides of the leaf spring 38 are arranged to restrict the position of theleaf spring against its resilience. The arrangement imparts an initialforce to a protruding part 38a of the leaf spring 38. Under thatcondition, the protrudent part 38a comes to the upper part of thespindle 6.

A spring 13 which is provided on the above stated hinge shaft 12 has itsarm parts abut on the holder 31 and the outer cover 35 respectively andis arranged to exert a turning force on the cover 35 in the direction ofopening it relative to the holder 31. A spring 14 has one arm partthereof abut on the body chassis 11 and the other arm part abut on theouter cover 35 and is thus arranged to exert a counterclockwise turningforce on the outer cover 35. A normally open type outer cover lockcompletion detecting switch 74 which is mentioned in the foregoing isprovided on the body chassis 11 and is arranged to have its contactpiece 74a pushed by the switch control arm 23d of the lock lever 23.Under the condition as shown in FIGS. 15c and 16c, its contact pieces74a and 74b come into contact with each other.

Referring to FIG. 17, memory means for mechanically storing informationon a replacing action performed on the cassette 1 (by loading andunloading) is arranged as follows: A shaft member 61 which is arrangedto pivotally carry a lever is secured to the reverse side of a top boardof the chassis 11. A switch operation lever 62 is pivotally andswingably carried by the shaft part 61a of the pivotally carrying shaftmember 61. The fore end of the lever 62 is formed into a switchoperation part 62a which is bent in such a way as to be located abovethe contact piece 70a of the switch 70 when it is in a neutral state. Aspring 63 is arranged to urge the lever 62 to turn counterclockwise asviewed on the drawing and to keep it in a neutral state. The spring 63is wound round the shaft part 61a of the pivotally carrying shaft member61. Two ends of the spring 63 are hooked on the lever 62 and a fixed pin65 respectively. The pin 65 is arranged to restrict the counterclockwiseturn of the lever 62 by engaging the tail end 62b of the lever 62 whenthe switch operation part 62a just comes above the contact piece 70a ofthe switch 70. A member 64 is a retaining member arranged to prevent thespring 63 and the lever 62 from pulling out off the member 61.

A cassette loading/unloading detection lever 66 is formed approximatelyin an L shape and is provided with a cassette sensing piece 66a at thefore end thereof. A shaft 67 pivotally carries the lever 66. A spring 68is arranged to urge the lever 66 to turn counterclockwise as viewed onthe drawing. The cassette sensing piece 66a is thus pushed by the spring68 to protrude toward the holder 31 through a hole 11b provided in thetop board of the chassis 11. Further, the lever is provided with adownward protrudent part 66b which is arranged to abut on the arm part62c of the switch operation lever 62; a downward pushing part 66c whichis arranged to push downward the arm part 62c of the lever 62; and aswitch operation part 66d which is arranged to push down the contactpiece 69a of the switch 69.

The switch 69 is a normally-open type cassette presence/absencedetecting switch. When the apparatus is loaded with no cassette, thecassette loading/unloading detection lever 66 is turned counterclockwiseby the spring 68. Then, the switch operation part 66d pushes the contactpiece 69a of the switch 69 to move it away from the contact piece 69b.The switch is thus brought into an OFF state. When the apparatus isloaded with the cassette 1, the lower side of the cassette 1 turns roundthe sensor piece 66a of the lever 66 clockwise as shown in FIGS. 15B and15C. Then, the contact pieces 69a and 69b of the switch 69 come intocontact with each other to bring the switch 69 into an ON state.

The switch 70 is a normally open type cassette loading/unloadingdetecting switch. The switch 70 turns on when the switch operation part62a of the switch operation lever 62 pushed down the contact piece 70ato bring it into contact with another contact piece 7b.

A gear 71 is rotatably carried by a shaft 72 to rotate according as thehead 5 is shifted by a head shifting device which will be describedlater herein. A reset lever 73 is provided with an uprising part 73a.When the head 5 is shifted to a given position outside of apredetermined recording area on the magnetic disc 2 by the head shiftingdevice, the uprising part 73a pushes the tail end 62b of the switchoperation lever 62 to turn round clockwise against the force of a spring63 until the arm part 62c of the lever 62 comes to part from thepushing-down part 66c of the cassette loading/unloading detection lever66.

In loading the apparatus with the cassette 1, the outer cover 35 isfirst opened by turning it round counterclockwise on the hinge shaft 12with the aid of the urging force of the spring 14 relative to the bodychassis 11. Then, the outer cover 35 comes to a stop with one end 35bcoming to abut on the wall 11a of the chassis. In this instance, theholder 31 which is under the urging force of the spring 13 tries to turnround clockwise relative to the outer cover 35. However, this isprevented by the hook member 40 of the outer cover 35 which thenrestricts the holder to its position as shown in FIG. 15A.

When the outer cover 35 and the holder 31 are in the open state as shownin FIG. 15A, the clamping lever has its hook part 18b in a state ofengaging the claw part 21d of the lock lever 21. The bent part 21c ofthe lock lever 21 is then abutting on one end 23c of another lock lever23. The two lock levers 21 and 23 are thus in a state of having beenshifted to the right into an interlocked position. The claw parts 21a,23a, 21b and 23b of the two lock lever 21 and 23 are located outside ofthe moving loci of the lock pins 36a and 36b erected on the outer cover35. Under this condition, the above stated lock completion detectingswitch 74 has its contact pieces 74a and 74b staying away from eachother.

Further, under this condition, as shown in FIG. 17, the cassetteloading/unloading detection lever 66 is in a state of having been turnedround counterclockwise by the force of the spring 68. Therefore, theswitch operation lever 62 is released from the restriction imposed bythe downward extending part 66b of the detection lever 66 and is allowedto be turned round counterclockwise by the force of the spring 63 untilits tail end 62b comes to impinge on the pin 65. Then, the switchoperating part 62a of the lever 62 is positioned immediately above thecontact piece 70a of the cassette loading/unloading detecting switch 70.Meanwhile, the cassette presence/absence detecting switch 69 has itscontact pieces 69a and 69b parted from each other with the former pusheddown by the switch operating part 66d of the lever 66.

Again referring to FIG. 15A, with the cassette 1 inserted into theholder 31 via its opening part 31f under the illustrated condition, whenthe outer cover 35 is turned round clockwise on the hinge shaft 12against the urging force of the spring 14, the holder 31 also turnsround in the same direction on the hinge shaft 12. Then, when they cometo a point where a cassette and disc loading action is completed asshown in FIG. 15C, the spindle 6 enters the engaging hole 3c of thecenter core 3 of the magnetic disc 2 through the aperture 31c of theholder 31. The lower and upper stabilizer plates 15 and 37 also enterthe apertures 1b and 1a through the apertures 31b and 31a of the holder31 respectively. Then, when the outer cover 35 is pushed further in thedirection of arrow as shown in FIG. 15B from the cassette and discloading completed position of FIG. 15C, the center core 3 of themagnetic disc 2 is urged to move to the spindle 6 by the fore endprojection 38a of the leaf spring 38 attached to the outer cover 35. Thelower surface of the center core 3 then comes into contact with theflange face 6b of the flange part 6a of the spindle 6. At that time, adifference between the pushed extent of the outer cover 35 and anecessary extent to which the center core 3 is to be pushed down isabsorbed by the flexion of the leaf spring 38.

With the cassette 1 inserted in the holder 31, the lower side of thecassette 1 pushes the cassette sensor piece 66a of the cassetteloading/unloading detection lever 66 shown in FIG. 17 under thecondition which obtains as shown in FIGS. 15B and 15C. This causes thelever 66 to turn round clockwise against the force of the spring 68.Then, the pushing-down part 66c of the lever 66 pushes the arm part 62cof the switch operation lever 62. The switch operating part 62a of thelever 62 then pushes the contact piece 70a of the cassetteloading/unloading detecting switch 70 to bring it into contact with thecontact piece 70b. The switch 70 is thus turned on. At that time, thecassette presence/absence detecting switch 69 is released from thedepressing action of the lever 66 on its contact piece 69a and isallowed to turn on by itself. If the cassette 1 is not inserted in theholder 31, the detection lever 66 is not turned round clockwise. In thatevent, therefore, both the switches 69 and 70 are left in their OFFstates.

As described in the foregoing, the embodiment is arranged to storeinformation about removal of the cassette 1 by turning round the switchoperation lever 62 to a position where its arm part comes beneath thepushing-down part 66c of the cassette loading/unloading detection lever66. A memory signal for this is obtained in the form of an ON state ofthe cassette loading/unloading detecting switch 70 by setting the armpart of the lever 62 with the arm part pushed down together with theouter cover 35 to a state as shown in FIGS. 15B and 15C and with thecassette 1 placed within the holder 31.

When the outer cover 35 is pushed in as shown in FIG. 15B, the lock pins36b which is one of two lock pins 36a and 36b provided on the outercover 35 comes to push down the tail end 18a of the clamping lever 18.This causes the lever 18 to turn round counterclockwise on the shaft 17against the force of the spring 19. The hook part 18b is thus disengagedfrom the claw part 21d of the lock lever 21. This disengagement allowsthe lock lever 21 to be moved by the urging force of the spring 22 tothe left as shown in FIG. 16B. Then, the claw parts 21a and 21b of thelock lever 21 come to the upper ends of the lock pins 36a and 36b. Theside edge part of the claw part 23a or 23b of the lock lever 23 comes toimpinge on one side part of the lock pin 36a or 36b. This prevents thelock lever 21 from being moved to the left by the spring 24. The locklever 23 is thus stopped while the other lock lever 21 is moving. Afterthis, when the outer cover 35 is released from a pushing operationperformed thereon, the urging force of the spring 14 tries to turn roundthe cover 35 counterclockwise on the hinge shaft 12. At this time,however, the lock pins 36a and 36b engages the claw parts 21a and 21b ofthe lock lever 21 to inhibit the cover 35 from turning. Further, at thistime, the lock lever 23 is caused by the urging force of the spring 24to move to the left until the leftward move is prevented by the bentpart 21c of the lock lever 21. As a result, the claw parts 23a and 23bengage the lock pins 36a and 36b respectively as shown in FIG. 16C. Inother words, the outer cover 36 is thus secured to the body chassis 11at that point of time. Under this condition, the switch control arm 23dof the lock lever 23 turns the lock completion detecting switch 74 intoan ON state by bringing its contact piece 74a into contact with itsanother contact piece 74b. Further, the fore end projection 83a of theleaf spring 38 attached to the outer cover 35 parts from the center core3 as shown in FIG. 15C. The magnetic disc 2 is thus adequately mountedon the spindle 6 and is ready to be rotated by the rotation of thespindle 6.

In taking out the cassette 1, the bent part 21e of the lock lever 21protruding from the slot-like opening 16a provided in the side plate 16is pushed to the right against the forces of the springs 22 and 24 (seeFIG. 16C). This brings the lock lever 21 into a state of being locked bythe clamping lever 18 as shown in FIG. 16A. The lock lever 23 then comesback to its original position to open the switch 52. At the same time,the outer cover 35 and the holder 31 are brought into the state of FIG.15A by the actions of the springs 13 and 14. Further, in this instance,the switch 120 turns on soon after the lock lever 21 is operated.

In FIGS. 15A, 15B and 15C, a reference numeral denotes a cassettepositioning member. This member 43 is disposed in the bottom part withinthe holder 31. A leaf spring 44 or the like is preferably arranged, forexample, on the ceiling part of the outer cover 35 to push the cassette1 toward the positioning member 43 when the outer cover 35 is closed. Ina modification of the above stated cassette and disc loading device, theholder 31 is omitted and, in place of the holder, a fixed cassettereceiving part is formed, within a space on the chassis 11 between thehinge shaft 12 and the side plate 16, in the shape of a frame or thelike corresponding to the cassette 1. The cassette 1 then can be putinto the cassette receiving part. In the case of this modification, theouter cover 35 is provided, for example, with some elastic member whichis made of a leaf spring, a sponge material or a soft rubber materialand is arranged to push the cassette 1 against the body chassis whilethe outer cover 35 is in a locked state, so that the cassette 1 can bekept in a state of being fixed to the chasis 11. Further, in thatinstance, it is preferable to add some ejecting means which is arrangedto eject the cassette 1 from the cassette receiving part in response toan opening action performed on the outer cover 35.

Further, in an example of modification of the memory or storing meansshown in FIG. 17, only the switches 60 and 70 and the gear 71 aredisposed on the side of the body chassis while the operation lever 62and the detection lever 66 are disposed on the reverse side of theholder 31 in the manner as shown in FIG. 17. The cassette sensor piece66a of the detection lever 66 is arranged to enter into the holder 31through the aperture 31g of the holder 31. The levers 66 and 62 are thusarranged to become operable on the switches 69 and 70 when the holder 31and the outer cover 35 are set in the states as shown in FIGS. 15B and15C. In this instance, a reset lever 73 may be arranged to act on thelever 62.

Referring now to FIG. 18, the magnetic head shifting device is arrangedas described below:

The magnetic head 5 is secured to a slot part 46c of a head carrier orcarriage 46 via a head mount plate 9. The head carrier 46 is arranged tobe guided through sliding balls 48 by guide rails 47 and to be slidablealong the guide rails 47. The balls 48 are inserted in between V-shapedgrooves 46e and 47a formed along the edges of the guide rails 47 andthose of the head carrier 46. A slot 46d is provided in the head carrier46 for an escape from the spindle 6. The head carrier 46 has an engagingpart 46b which is arranged at the fore end of the arm part 46a of thehead carrier 46 to engage a head shifting screw 54. A back-lash removingspring 56 is provided in between the arm part 46a and a fixed pin 57.The spring 56 urges the carrier 46 in the direction of arrow X, ordownward as viewed on the drawing, and is arranged to remove anyback-lash of engagement between the engaging part 46b and the screw 54.

The screw 54 is mounted on the shaft 51 in the middle part thereof andis rotatably carried by a bearing 52. Worm wheels 53 and 55 are mountedon the two ends of the shaft 51. The worm wheel 53 engages a worm gear50 which is mounted on the output shaft 49a of the head shiftingstepping motor 49. Meanwhile, the worm gear 55 engages the gear 71 whichis shown in FIG. 17.

Therefore, when the stepping motor 49 rotates, its rotation istransmitted via the engagement of the worm gear 50 and the worm wheel 53to the shaft 51. This causes the screw 54 to rotate. The carrier 46 isthen moved through the engagement of its engaging part 46b and the screw54 to an extent according to the lead of the screw 54. In that instance,the moving direction of the carrier 46 is determined by the rotatingdirection of the motor 49. The shifting extent of the head carrier 46corresponding to the unit track pitch on the disc 2 is determinable by anumber of steps of rotation of the motor 49. The gear 71 is rotatedthrough the worm gear 55.

Detectors 58 and 59 are arranged to detect that the head 5 comes to theoutsides of a given recording area of the disc 2 on the peripheral sideand the center side thereof. Each of the detectors is arranged in thesame manner as the arrangement of a known photo coupler consisting of alight emitting element 58a or 59a and a light receiving element 58b or59b and is arranged to detect a light shielding plate 46f or 46g whichis mounted on the head carrier 46.

The description given hereinafter is on the assumption that the disc 2is arranged to have a total of 50 recording tracks formable within thegiven recording area thereof at a predetermined pitch of, for example,100 μm. These recording tracks are numbered in sequence from 1 to 50from the peripheral side to the central side of the disc. In this case,the detector 58 is arranged to detect the light shielding plate 46f whenthe head 5 is shifted to a position one track pitch distance closer tothe periphery of the disc than the first track (hereinafter thisposition is referred to as the 0-th track position for the sake ofconvenience). The other detector 59 is arranged to detect the lightshielding plate 46g when the head 5 is shifted to a position one trackpitch distance closer to the center of the disc than the 50th track(hereinafter that position is referred to as the 51st track position).Further, the gear 73 is arranged to be rotated clockwise(counterclockwise as viewed on FIG. 17) when the head carrier 46 is tobe moved in the direction of arrow X of FIG. 18 and to be rotatedcounterclockwise (clockwise in the case of FIG. 17) when the headcarrier 46 is to be moved in the direction reverse to the direction ofarrow X. In that case, the reset lever 73 is arranged to disengage thearm part 62c of the switch operation lever 62 from the pushing-down part66c of the detection lever 66 by pushing the tail end 62b of the lever62 with its uprising part 73a when, for example, the head 5 is shiftedto an extent corresponding to five track pitches (5 TPs) further towardthe central side of the disc from the above stated 51st track position.Further, the head carrier 46 is moved in the direction of arrow X by theforward rotation of the stepping motor 49 and in the reverse directionby the reverse rotation of the motor.

Referring to FIG. 19, an example of modification of the flow ofoperation shown in FIG. 2 is described as follows: The descriptionplaces emphasis on the steps arranged to increase the accuracy and speedof the check made at the step S09 of FIG. 2 for the presence or absenceof a record existing on the magnetic disc 2.

In the modification shown in FIG. 19, a step S08' follows the step S07of FIG. 2 while a step S20 follows the step S14' of FIG. 2. Other stepsof this modification are similar to the corresponding steps of FIG. 2and, therefore, are omitted from description given here. After the stepS07 of FIG. 2, the flow comes to the step S08', at which the controller91 instructs the driving circuit 87 to have the motor 49 immediatelymake stepwise forward rotation to an extent corresponding to five TPs (5track pitch distance) in the direction of arrow X. The reset lever 73 ofFIG. 17 then causes the switch operation lever 62 to turn roundclockwise. The arm part 62c of the lever 62 then moves away from thepushing-down part 66c of the cassette loading/unloading detection lever66. Then, the cassette loading/unloading detecting switch 70 comes backto its OFF state. Meanwhile, the spring 63 acts to bring the arm part62c of the operation lever 62 back to its neutral position where thedownward-extending part 66b of the detection lever 66 can impinge uponthe arm part 62c. After that, therefore, the operation lever 62 nolonger acts on the switch 70 with the downward-extending part 66c of thedetection lever 66 impinging thereon even when the lever 62 is releasedfrom the pressure of the reset lever 73.

After the stepping motor 49 has made the stepwise forward rotation tothe extent of five TPs, the controller 91 instructs the driving circuit87, at the step S09', to cause the motor 49 to make stepwise reverserotation in the direction reverse to the direction of arrow X. Thisbrings the head 5 to the 51st track position on the disc 2. The flow ofoperation then comes to a step S10'.

Step S10': The controller 91 causes the changeover switch 86 to shiftits connecting position on the side of the terminal C thereof. StepS11': Under this condition, the controller instructs the driving circuit87 to have the motor 49 shift the head 5 to an extent of one TP in thedirection reverse to the direction of arrow X by reversely rotatingstepwise. The head 5 is thus set in the 50th track position. Step S120':After that, the flag n is set at n=0 and the timer T is reset. Underthis condition, the record presence/absence detecting circuit 85 is inconnection with the head 5 via the changeover switch 86. The detectingcircuit 85 detects, at the timing of the FG pulses, the presence orabsence of any existing record on the disc 2 (in the 50th track in thisinstance) on the basis of a signal picked up by the head 5. The circuit85 then produces a signal at a high level in case of the presence of anexisting record and at a low level if no existing record is detected.Step S121': The controller 91 checks the level of the output of theabove stated detecting circuit 85 upon receipt of every FG pulse. If theoutput level is found to be high, the flow of operation comes to a stepS122'. Step S122': One is added to a number n of high level parts of theoutput every time a high level part is found. Step S123': When thisnumber n becomes n≧x, the track checked is considered to have anexisting record and the flow comes to a step S14'. In the event of n<x,however, the flow proceeds to a step S124'. Step S124': A check is madeto see if the period of time T required for one turn of the disc haslapsed. If not, the flow comes back to the step S121'. If the time T isfound to have lapsed, the track under the check is considered to have noexisting record and the flow proceeds to a step S13'. Step S13': A checkis made to see if the carrier position detector 58 of FIG. 6 (or itslight receiving element 58b) has been turned off by the light shieldingplate 46f for the purpose of confirming the arrival of the head 5 at the0-th track position. If not, the flow comes back to the step S11' toagain give the instruction to have stepwise reverse rotation of themotor 49 for shifting the head to the extent of one TP in the directionreverse to the direction of arrow X. In this instance, the value xindicated above represents an integer which is smaller than the numberof FG pulses obtained per turn of the disc. In the case of this specificembodiment, the number of FG pulses per turn of the disc is arranged tobe 15 and the value x is set at 5. The steps S11', S120' to S124' andS13' are repeated until either there obtains the state of n≧x or thedetector 58 turns off. After that, the flow comes to a step S14'. StepS14': An instruction is given to have the motor 49 make stepwise forwardrotation for shifting the head 5 to the extent of one TP in thedirection of arrow X, because: The state of n≧x indicates the arrival ofthe head 5 at a recorded track located in the last place among therecorded tracks on the disc 2 counting them in the sequence of tracknumbers. Therefore, when the flow of operation comes from the step S123'to the step S14', the head 5 is set at an unrecorded track locatedimmediately adjacent to the last of the recorded tracks. In other words,in this instance, some of the tracks on the disc 2 have already beenrecorded. Meanwhile, the OFF state of the detector 58 indicates thearrival of the head 5 at the 0-th track on the disc 2. Accordingly, thehead 5 is positioned at the first track on the disc 2 when the flowcomes from the step S13' to the step S14'. In other words, in thatinstance, the disc 2 has no existing record. The embodiment shown inFIG. 19 is arranged to drive the motors 49 and 88 by using the (speedsignal) FG pulses and to detect the presence or absence of records asmentioned above. The arrangement of this embodiment, therefore, obviatesthe necessity of forming any special synchronizing signal at asynchronizing signal generator and thus permits simplification ofcircuit arrangement. If it is necessary to form such a synchronizingsignal by means of a microcomputer, the program would become complex.Whereas, the use of the FG pulses in the above stated manneradvantageously simplifies the program.

With the head 5 thus having been set at an unrecorded track locatedimmediately after the last of the recorded tracks counting the recordedtracks in the sequence of track numbers, the flow of operation of thecontroller 91 comes to the step S20 of FIG. 2.

A modification of the flow of operation shown in FIG. 19 is arranged asshown in FIG. 20:

The same steps as those shown in FIG. 19 are omitted from description.Step S125': Following the step S11, the value B is set at B=0 and thetimer T is reset. The flow proceeds to a step S126'. Step S126': The RFdetection output level is sampled at the timing of the FG pulses for anapplicable track. A sampled value obtained at each FG pulse is assumedto be A. Step S127': The value A is added to the value B and is replacedwith the value B. Step S128': A check is made to see if the accumulatedvalue B has reached at least a certain level y. If so, the RF is assumedto be present in the track and the flow proceeds to a step S14'. StepS14': The same check is made for a next track. If the accumulated valueB has not reached the level, the flow comes to a step S129'. Step S129':A check is made to see if a period of time required for one round of thetrack has lapsed. If not, the flow comes back to the step S126'. If so,the flow proceeds to the step S13'. Therefore, like in the case of thepreceding example of embodiment, a next track can be checked withoutfurther examining all the points of the FG pulses in case that thepresent track is a recorded track. This arrangement shortens a period oftime required for detection. The arrangement may be changed to selectseveral points of the FG pulses and to determine the RF to be present ifthe average of the sampled values is not lower than a given value of theRF level.

In the case of the embodiment shown in FIGS. 19 and 20, the signallevels of varied points within each track are detected one afteranother; and the track is discriminated as to whether it is a recordedtrack without waiting for the result of detection of the signal levelsat all the points of the track being checked as soon as the result ofdetection is found to have reached a given reference level. Therefore, adiscrimination between a signal recorded track and an unrecorded trackcan be made in a short period of time. Further, since the presence orabsence of signals in the tracks are examined according to the timing ofthe FG pulses, the operation of the apparatus is not easily affected bya drop-out. Besides, since the embodiment does not necessitate anyspecial synchronizing signal, it permits simplification of itsstructural arrangement.

In the foregoing, a video signal recording operation to be performedwith the recording trigger switch 95 turned on after the completion ofpreparation for recording has been described with reference to FIG. 4.In case where the system controller 91 is connected to a mode selectionswitch 97. The recording operation is performed as described below withreference to FIG. 21:

The mode selection switch 97 is provided for selection between a singleshooting mode in which one field or frame portion of video signal isrecorded by one performance of operation on the recording trigger switch95 and a continuous shooting mode in which recording is repeated at agiven speed as long as the trigger switch 95 is kept in its ON state.The single shooting mode is selected when the switch 97 is in an OFFstate and the continuous shooting mode when the switch 97 is in an ONstate. FIG. 21 is a flow chart showing the recording operation to beperformed in this instance.

Step S31': After completion of the preparation processes which areperformed for recording as described in the foregoing, the controller 91repeats checking for the ON state of the recording trigger switch 95brought about by the second step stroke of a depressing operation on thetrigger button 96 as long as the power supply remains on. Step S32':When the trigger switch 95 is turned on, the controller 91 shifts theconnecting position of the change-over switch 86 to its terminal R. StepS33': Following this, the camera part 81 and the synchronizing signalgenerating circuit 84 are actuated. At the same time, the motor controlcircuit 89 is instructed to rotate the disc motor 88. The camera part 81then comes to produce a video signal in synchronism with thesynchronizing signals HS and VS coming from the synchronizing signalgenerating circuit 84. The recording circuit 82 processes the videosignal received from the camera part 81 (frequency modulation, etc.)into a recording signal. Under this condition, the recording gate withinthe recording circuit 82 is in an OFF state. Therefore, although thehead 5 is in connection with the recording circuit 82 via thechange-over switch 86, no recording is performed. Meanwhile, the motorcontrol circuit 89 receives the speed signal FG from the motor 88, therotation phase signal PG from the rotation phase detector 90 and thevertical synchronizing signal VS from the synchronizing signalgenerating circuit 84. The circuit 89 then controls the rotation of themotor 88 on the basis of these signals in such a manner that the motor88 rotates the disc 2 at a speed corresponding to the field or framefrequency and at a predetermined phase relative to the verticalsynchronizing signal VS. When the motor 88 comes to rotate at thecontrolled speed and phase, the motor control circuit 89 producesservo-lock-in signal SL at a high level. Step S34': In the meantime,after giving the instruction for the operation of the motor 88, thecontroller 91 repeats making a check to see if the level of theservo-lock-in signal SL from the control circuit 89 becomes high. StepS35': When the level of the signal SL becomes high, a recording triggersignal is promptly applied to the recording control circuit 83. Inresponse to this, the recording control circuit 83 turns on therecording gate of the recording circuit 82 and have it open for onefield or frame period including a vertical synchronizing signal firstobtained after receipt of the recording trigger signal on the basis ofthe synchronizing signals HS and VS coming from the synchronizing signalgenerating circuit 84. As a result of this, one field or frame portionof a recording signal is applied via the change-over switch 86 to thehead 5. The head 5 records the amount of signal on the disc 2 just inone turn of the disc 2 which is rotated by the motor 88. In thisinstance, the vertical synchronizing signal VS is recorded of course ina rotatory position predetermined relative to the vertical synchronizingsignal.

After completion of recording of one field or frame portion of the videosignal, the recording control circuit 83 produces a recording completionsignal RE at a high level. Step S36': Meanwhile, after the recording istriggered, the controller 91 repeats checking this recording completionsignal RE for a high level thereof. Step S37': When its level becomeshigh, the controller instructs the motor driving circuit 87 to cause thestepping motor 49 to make stepwise forward rotation in such a manner asto bring the head 5 to a next recording position by shifting it to theextent of one TP in the direction arrow X. Step S38': The controller 91checks the mode selection switch 97 for its ON state. Step S39': If theswitch 97 is not in the ON state (thus indicating selection of thesingle shooting mode), the controller 91 renders the camera part 81 andthe synchronizing signal generating circuit 84 inoperative and instructsthe motor control circuit 89 to bring the disc motor 88 to a stop. StepS40': Following this, the controller 91 checks the detector 59 to see ifit has been tuned off by the above stated shift of the head 5. If so,the flow comes to a step S41'. Step S41': The controller 91 causes thedisplay device to make a display indicative of the end of the disc. StepS42': Then, further recording is inhibited. With the switch 97 in theOFF state thus selecting the single shooting mode, the above statedsteps of operation are executed every time the recording trigger switch95 turns on to have one field or frame portion of the video signalrecorded in each of different positions on the disc 2 as long as thedetector 59 does not turn off.

In case that the mode selection switch 97 is found in its ON state atthe step S38' thus indicating selection of the continuous shooting mode,the flow comes to a step S43'. Step S43': The controller 91 checks thetrigger switch 95 to see if it is in an ON state. If not, the flowshifts to the previous step S39'. If so, the flow comes to a step S44'.Step S44': A check is made to see if the detector 59 is in its OFFstate. If not, the flow comes to a step S45'. Step S45': A wait time isprovided for a predetermined period of time Δt required for determininga speed or rate of a continuous recording operation. After the lapse ofthis wait time, the flow comes back to the previous step S35', at whichrecording is triggered once again. If the detector 59 is found in itsOFF state at the step S44', the flow comes to a step S46'. Step S46':The controller 91, like in the case of the step S39', causes the camerapart 81 and the synchronizing signal generator 84 to stop operating. Atthe same time, an instruction is given for bringing the motor 88 to astop. After that, the flow shifts to the step S41'.

With the switch 97 in its ON state thus designating the continuousshooting mode, one field or frame portion of the video signal iscontinuously recorded in each of different recording positions on thedisc 2 at the predetermined speed through the above stated steps ofoperation until the detector 59 turns off as long as the recordingtrigger switch 95 remains in its ON state.

Further, in this instance, the speed or rate at which the continuousshooting is to be performed is variable by adjusting the wait time Δtwhich is arranged to be determined at the step S45'.

What is claimed is:
 1. A still image pickup apparatus, comprising:a)means operable for converting a still image into a still imageelectrical signal; b) means for recording said still image electricalsignal on a recording medium; c) means operable for driving saidrecording medium relative to said recording means; d) means fordetecting loading, unloading and replacement of said recording mediumfollowing unloading thereof; e) means for determining whether saidconverting means and said driving means are operable; and f) means forinhibiting said driving means from operating when said detecting meansdetects unloading of said recording medium.
 2. An apparatus according toclaim 1, wherein said converting means includes:an image sensingelement; and an optical system for imaging a radiation from an objectonto said image sensing element.
 3. An apparatus according to claim 1,wherein said recording medium is a disc-shaped medium and said drivingmeans rotates said recording medium.
 4. An apparatus according to claim1, wherein said indicating means includes a manual operation member. 5.An apparatus according to claim 1, wherein said inhibiting meansincludes a CPU.
 6. A still image pickup apparatus, comprising:a) meansfor converting an image of an object into a still image electricalsignal, by using a given electric power, and for recording the stillimage electrical signal on recording means; b) means for detectingwhether said recording means is and is not loaded in said apparatus andwhether said recording means has been reloaded following unloadingthereof; and c) controller means for controlling the supply of saidelectric power in said apparatus on the basis of detection effected bysaid detecting means.
 7. An apparatus according to claim 6, wherein saidcontroller means is arranged to stop the supply of said electric powerin said apparatus when said detecting means detects that said recordingmeans is not loaded in said apparatus.
 8. An apparatus according toclaim 6, wherein said recording means includes:a recording medium onwhich said still image electrical signal is to be recorded; and drivingmeans for driving the recording medium.
 9. An apparatus according toclaim 8, wherein said control means is arranged to stop supplying ofelectric power to said driving means when detecting means detects thatsaid recording means is not loaded in said apparatus.
 10. An apparatusaccording to claim 6, further comprising:electric power supply means forsupplying said electric power.
 11. An apparatus according to claim 6,further comprising:reproducing means for reproducing the still imageelectrical signal recorded by said recording means.